ohh wow, that's gotta be one of the longest posts i've read in a while, but i did read the whole thing. Alot of your questions will be better answered by the new GTO guys, but i guess we should start with the, "is a gto too much car for a 17 year old?" generally the answer is YES. Nobody on here wants to see another GTO in the ditch, or in an accident. so you will see a good number of people try to convince you otherwise. I am 19, and know i know my way around a good number of high powered cars, and can ussually gain a tenth or two by just jumping in a buddy's car at the strip. If you learn how to drive on the M6, you may end up like this poor kid:
YouTube - Kid crashes father's new Mustang into garage
as far as terminology....
LTs = long tube headers = exhaust manifolds that are very free flowing (not to be confused with shorties)
cat = catalytic converter= makes your car more environmentally friendly (and restricts exhaust flow)
alot of acronyms you will hear may refer to colors, or transmissions (M6 = manual six speed, A4 = automatic 4 speed)
I would stray away from performance mods as expensive as you have mentioned, because, i believe that you will already be a little overwhelmed with a bone stock GTO. With your limited automotive experience, im still not sure a GTO is the right car for you.
